var tow = document.getElementById("tow");
var thiree = document.getElementById("thiree");
var choice = document.getElementById("choice");
var cho = document.getElementsByName("cho");
var show = document.getElementById('show');
var refurbish = document.getElementById('refurbish');
var pi = Math.PI;
var PI = Math.PI;
var clearNumber = 1;
refurbish.onclick = function () {
    location.reload();
}

/*
 *扩大坐标轴4倍
 */
function enlargeAxes(mycanvas, context, dim) {
    if (clearNumber != 1) {
        context.restore();
    }
    context.save();
    context.fillStyle = "black";
    context.clearRect(-mycanvas.width / 2, -mycanvas.height / 2, mycanvas.width * 4, mycanvas.height * 4);
    context.translate(-mycanvas.width / 0.675, -mycanvas.height / 0.675);
    context.scale(4, 4);
    if (dim == 2) {
        drow2DAxes(context);
    } else {
        drow3DAxes(context);
    }
    clearNumber++;
}



